The present invention relates to copy production machines and particularly to those machines capable of having multiple copy runs in a copy sheet transport path at a given instant. In particular, the invention pertains to recovery from error conditions in such a machine.
The performance of copy production machines has been continually increasing, particularly copy production machines that have the capability of simultaneously processing copies of multiple images with the result that recovery from a jam condition in a copy production machine has become quite complicated. Not only must the lost copies be recovered but they must also be identified with an image carried by the lost copies. The situation becomes more complicated when duplex copying is provided in such machines. In such situations the machine must know whether the first or second side is being produced as well as the number of good copies remaining in an interim storage unit storing the single-imaged copies.
All of these problems are compounded in rental copy production machines because the user should not pay twice for a copy produced or be able to manipulate the machine to avoid the rental charges. Recovery from jam conditions also should be set up so that the calculations are relatively simple. Furthermore, in the copy production machines of the convenience copier type, i.e., ones without a fully automatic recirculating document feed, suitable instructions have to be provided for the operator to achieve successful jam recovery. Such procedures should be simple so that a relatively untrained operator can achieve copy jam recovery. With the advent of using programmable processors in the control of copy production machines, the procedures involved should be amenable to computer program implementations.